Altering the image signal to present the viewer additional information or insight into factors concerning the pre-enhanced image are known. For example, two useful image enhancement operations are noise reduction and edge sharpening. Various filtering techniques for reducing noise have been proposed. For example, in U.S. Pat. No. 3,009,016--Graham there is described a noise reduction system in which a running average of picture samples (pixels) is compared with each new sample of the video signal, and if the picture sample does not exceed a predetermined theshold, the average of the samples is substituted. In copending application Ser. No. 133,606 filed Mar. 24, 1980, entitled "Adaptive Enhancement of Signal-to-Noise Ratio in Television Imagery," assigned to the same assignee as the present application, there is described a refined noise reduction system which generates an average from samples over an area extending both vertically above, and horizontally back from the current sample of the video signal. While both of these arrangements improve picture quality by reducing noise in areas of the picture which have relatively low detail and uniform intensity, they provide no enhancement by sharpening the edge between regions of contrasting intensity. Noise filtering and image sharpening involve conflicting requirements since filtering to reduce noise can blur the image while circuits for enhancing image sharpness will also enhance the noise.